GlossaryGrowth & analytics
What is retention?
Also called: user retention, customer retention, retention rate, retention curve, net revenue retention
Definition
Retention is the share of users or customers who keep using or paying for your product over time, usually measured for a cohort that started in the same period. It's the clearest signal that a product delivers lasting value.
Retention, explained
Acquisition fills a bucket; retention decides whether it leaks. A product that keeps 60% of users after three months can grow on modest acquisition. A product that keeps 5% has to replace almost every user, forever, which gets more expensive every month.
Measure it with cohorts. Take everyone who signed up in a given week or month and track what share are still active in each following period. Plot that as a curve. The most important feature of the curve is its shape: does it keep falling toward zero, or does it flatten? A curve that flattens means a group of users has found lasting value. That flat part is the foundation everything else is built on.
Define "active" in a way that reflects value, not just a login. For a weekly-use product, did they do the core action this week? For a monthly-use product like invoicing, did they send invoices this month? Choosing the wrong frequency makes retention look better or worse than it is.
There are revenue versions too. Customer or logo retention counts paying accounts that stay. Net revenue retention (NRR) compares revenue from a cohort now against the start, including upgrades, downgrades and churn; above 100% means existing customers are growing faster than you lose them.
For early startups, retention is the best evidence of product-market fit you can get without asking anyone. Before investing heavily in launches, SEO or ads, it's worth knowing whether the users you already have stick.
Why it matters for founders
Every channel, from launches to SEO, gets more valuable when users stay. A flattening retention curve is the signal that more acquisition will actually compound.
Example
A habit-tracking app's monthly cohorts fall to 8% by month three and keep dropping. After adding reminders and streaks, the newest cohorts flatten at about 25%, and growth from the same traffic finally compounds.
Common mistakes
- Tracking total active users instead of cohorts.
- Counting logins as retention.
- Scaling acquisition before the retention curve flattens.
Sources
Checked
Related terms
- Churn rateChurn rate is the percentage of customers, or of recurring revenue, lost during a period. Monthly customer churn is customers who cancelled this month divided by customers you had at the start of the month.
- Cohort analysisCohort analysis groups users by a shared characteristic, usually when they started, such as sign-up week, and tracks each group's behavior over time, so you can compare how different groups retain, activate or pay.
- Activation rateActivation rate is the percentage of new users who reach a defined "activation" event, the first point where they get real value from your product, within a set time after signing up.
- Product-market fit (PMF)Product-market fit (PMF) is the point where a product satisfies a strong market demand: customers use it, keep using it, pay for it and recommend it, with growth pulling the company rather than being pushed.
- Customer lifetime value (LTV)Customer lifetime value (LTV) is an estimate of the total gross profit a business will earn from a typical customer over the whole time they stay a customer. It's compared with CAC to judge whether acquisition is worth it.